Design: A cross-sectional study among 100 FSW and 100 male clients in Preah Sihanouk Province, Cambodia. Half of the FSW (n=50) will be recruited in entertainment/drinking establishments (karaoke bars, beer gardens, and nightclubs) and the other half (n=50) in non-entertainment sex work venues (brothels, parks, streets, guest houses). Clients of FSW will also be recruited directly at entertainment/drinking establishments (n=50) and sex work venues (n=50). After an informed consent process, participants will be tested for HIV using rapid testing. Urine samples will be taken for drug toxicology. Dried blood samples (DBS) will be collected to detect heavy alcohol consumption using Phosphatidylethanol (PEth), a biomarker of alcohol intake. Vaginal samples will be collected from women to test for prostate specific antigen (PSA), a marker of recent unprotected sexual intercourse. A standardized questionnaire will be administrated to collect data on socio-demographics and sexual, alcohol and drug exposures. Results from this study will provide important preliminary data for a larger study aimed at reducing HIV risks in FSW and male clients in Cambodia.

Duration of the study: one year

Statistical analysis: The prevalence of alcohol and drug use, and exact binomial confidence intervals will be used to quantify the degree of uncertainty in the estimates. The synergy between alcohol and/or drug use (principally ATS) and each HIV risk outcome variables (HIV infection, inconsistent condom use, number of sex partners) by type of work venues will be examined using bivariate and multivariate analysis. Potential confounders and covariates will be tested and included into multivariate models.